APRIL 2016 MARKS THE centenary of the Dublin Easter Rising, when 1200 members of the Irish Republican Brotherhood (IRB) and Irish Citizen Army took over the centre of Dublin in armed rebellion against British rule. Initially caught unprepared, the authorities soon responded with a rapid build-up of troops and equipment. After six days of fighting, the rebels surrendered unconditionally.
The leaders were tried and executed. The rest were interred. Civilian reaction covered the whole spectrum from opposition through apathy to passive support and opportunistic looters –which both sides acted to prevent.
The only summary I can give is that Irish politics is complicated. Very complicated. But in among the complexities of the numerous Republican factions, each with their own agendas for an independent government, the part of the uprising of interest to divers is the story of a gun-running tramp steamer from Germany – now a notable dive-site in the approaches to Cork.
The Wilson Line’s ss Castro was built by the Earle’s Shipbuilding & Engineering Co of Hull in 1910. From 1911 to 1914 the 1228-ton Castro lived the normal life of a tramp steamer, carrying assorted cargoes between ports.
At the outbreak of war she was caught in the Kiel Canal and ordered into Hamburg to be impounded.

KARL SPINDLER WAS AN OFFICER in the German Merchant Marine who transferred into the Imperial German Navy. By 1916 he was a lieutenant commanding the patrol-boat Polarstern (Polar Star), operating with a flotilla of similar boats out of Wilhelmshaven.
In March 1916, tired of the monotonous patrols, Spindler volunteered for a secret mission, as did enough officers and men from the flotilla to provide his crew of 22.
Through the next few weeks Spindler was briefed and introduced to Sir Roger Casement, the IRB leader to whom he was to deliver arms in Ireland. His crew worked to prepare the Castro, renamed Libau as an auxiliary cruiser of the German navy but now disguised as the Norwegian steamship Aud.
Such camouflage had become a regular practice for German ships running the Royal Navy blockade. The Aud was picked because of a superficial resemblance, and because the real vessel was known to be away at sea.
The crew had to pass as Norwegian merchant seamen, too, adopting their names, dressing in well-used Norwegian clothing and losing all traces of German Imperial Navy cleanliness and discipline.
In his books The Mysterious Ship and The Mystery of the Casement Ship, Spindler writes of his steward, dressed in his scruffy clothes, presenting him with coffee on a tray in the official military manner and clicking his heels.
None of the crew spoke Norwegian so they spoke in “Low German”, which it was hoped the traditionally language-ignorant British would be unable to tell from Norwegian. Spindler and some of the crew could also speak English.
On 9 April the Aud left Lübeck carrying 20,000 Mosin-Nagant rifles, 10 Maxim machine-guns and 4 million rounds of ammunition.
The rifles, captured after the massive defeat of the Russian army at Tannenberg, were a robust and reliable repeating weapon comparable to the British Lee-Enfield and German Mauser-98. They were vastly superior to the single-shot rifles the Republicans had smuggled into Ireland before the war.
Over the next few days the Aud made its way out of the Baltic and north to the edge of the Arctic Circle. The route was designed to enhance the cover story of departing from Oslo.

THE ROYAL NAVY GUARDED entry to the Atlantic with a chain of cruisers patrolling between Scotland and Iceland. At the edge of the Arctic Circle, Spindler waited a day for foul weather to cover his way through. His course then led out into the North Atlantic before turning back for a navigational check at Rockall and approaching Ireland from the west.
From the Skagerak to Ireland the Aud was spotted and at times shadowed by several British cruisers, but none actually boarded.
Meanwhile Sir Roger Casement, Captain Robert Monteith and Sgt Daniel Bailey of the “Irish Brigade” were transported to Ireland by U-boat. After discussions at the German Embassy in the USA, Casement had originally travelled to Germany to establish a brigade of Republicans fighting for the German army, recruited from the many prisoners captured from the British forces. Captain Monteith was to be their commander. As it turned out, only 52 PoWs volunteered, including Bailey.
Casement’s transport was initially to have been on U20, the U-boat that had sunk the Lusitania, but hydroplane problems caused U20 to turn back, and the Irishmen were transferred to U19.
Surprisingly, even after mechanical failures and weather problems, both vessels arrived in Tralee Bay on schedule on Thursday 20 April, ready to rendezvous that night.
A Republican-crewed pilot boat would collect Casement and his colleagues from the U-boat and lead the Aud in to unload the cargo.
The rendezvous between U19 and the Aud never happened, most likely because the Aud was waiting in the wrong place.
Spindler had considerably less experience than Raimund Weisbach, commanding U19, of wartime navigation and of Irish waters. If you have ever dived off this coastline, you will know how confusing the numerous bays, peninsulas and islands can be.
Evidence that U19’s navigation was accurate is that the Republicans were landed in Tralee Bay. It was decided to put them ashore by dinghy, and at 2:15am on 21 April, Good Friday, they started rowing for shore.
They landed at Banna Strand, their dinghy overturning in the surf. Casement was unwell, either weakened by several days of seasickness or suffering a relapse of malaria. Monteith went on to contact Republicans ashore, leaving Casement in hiding.
In the morning the dinghy was discovered by a farmer and reported to the police. Casement was arrested at 1.30 that afternoon.
That morning the Aud was boarded at anchor from the British armed trawler Setter II. Karl Spindler writes that his crew played up the role of drunken Norwegians while he entertained the commander with large amounts of whisky.
British Admiralty records are less detailed, but note that Setter II was ordered to inspect a suspiciously acting Dutch ship but found it to be a harmless Norwegian.
At 1pm, HMT Lord Heneage appeared from the north. With the prospect of covertly landing the arms now gone, and little chance of fooling another boarding party, Spindler raised anchor and ran the Aud at full steam south-west, aiming to lose his pursuers in the Atlantic and become a commerce raider.

THE TRAWLERS COULDN’T overtake the Aud, but managed to keep her in sight while reporting the position. She was intercepted by the sloops HMS Bluebell and HMS Zinnia, 18 miles off Great Skellig at 6:30pm.
Unsure how well-armed the Aud was, HMS Bluebell escorted the ship to Queenstown, the naval port of Cork, from a safe distance. Approaching the estuary at 9.28am on 22 April, Spindler scuttled the Aud with pre-prepared charges, raising the German ensign and the crew donning their full uniforms before abandoning ship.
But what of the pilot-boat and Republicans who were to meet the Aud and unload the cargo?
The plan was for the rising to start on 23 April, Easter Sunday, and to reduce the risk of early discovery the arms were not to be landed before then.
At some point in the planning process this had either not been properly communicated, or plans had been changed after the Aud had left Germany. Both German captains understood that the arms were to be landed on 21 April.
The Republican harbour pilot had seen a ship at sea but two days early. Not seeing the agreed signal, he had not ventured out to meet it.
Already too late to meet the Aud, two cars containing Republicans from Dublin had become lost on the night of 21 April. One had driven off a pier and the occupants had drowned.
Since leaving Germany, Sir Roger Casement had become disillusioned with the whole operation, realising that without German troops to support it, the rising was doomed to failure.
Without the guns and with Casement’s plea to abandon the uprising, there was disagreement among the Republican leadership as to whether the rising should go ahead. This led first to a cancellation, then a delay to Easter Monday, and may also have been responsible for a lower turn-out than originally anticipated.
Would the Aud’s arms have enabled the Easter Rising to succeed?
That’s very unlikely. A better-armed rising with 10 times as many armed Republicans would simply have resulted in an even bigger and more overwhelming response from Britain, with many more deaths of both combatants and civilians. Ireland would have been devastated.

THE RESULT WOULD HAVE BEEN useful to the Germans, but everyone else would have lost. The only direct German military support was a raid by battle-cruisers on Lowestoft and Great Yarmouth on 25 April, ostensibly to divert British attention from Dublin.
Leaders of the rising were quickly tried by court martial and executed by firing squad within days of the surrender. Sir Roger Casement was taken to the Tower of London and tried for treason. He was hanged in Pentonville on 3 August, 1916.
Captain Monteith evaded capture and made his way to the USA.
Throughout the war, British Naval Intelligence had been remarkably effective. That a ship running guns to Ireland had left Germany on 9 April was known and, together with details of the planned rising, was reported to the Under-Secretary for Ireland on 17 April.
However, to protect methods and sources for future intelligence, details of the source were not included and the information was pushed aside. It wasn’t until Casement’s arrest and the scuttling of the Aud that the intelligence report was taken seriously. Permission to arrest the leaders was sought, but not approved until after the rising had started.
Conspiracy theorists allege that this was all deliberately allowed to go ahead, even that British cruisers spotting the Aud on its voyage had been ordered to report its position but let it continue.

ON THE REPUBLICAN SIDE, conspiracy theorists believe the leadership expected the rising to fail and engineered a bloody propaganda exercise to create martyrs. If so, it was a success. Recruitment increased and support grew for the successful guerrilla and political campaigns for independence that occurred after the war.
The wreck with its cargo of rifles and ammunition is now an easily accessible dive in 34m. First to dive it in 1916 was RN Diver CA Chard, tasked to recover samples of the munitions for intelligence analysis when the wreck was still intact.
He wrote in 1953 that “Diving on the Casement job was a wonderful experience; the deep blue colour of the water made the undersea scene weirdly beautiful.
“There was ample light, although the ship’s hold was black as Erebus and, having no torch, I had to work by touch.”
After the war, the wreck was depth-charged to render remaining armaments unusable and disperse it as any hazard to navigation.
The real Norwegian Aud was torpedoed by U18 on 30 November, 1916, 16 miles north of St Ives. The depth to the seabed is 62m and the wreck was identified by divers recovering the bell in 1983.
Karl Spindler became a persistent but ultimately unsuccessful escapee from Donnington PoW camp, then made a post-war career lecturing about his adventures in the USA. During WW2 he was interned in America.

You can book liveaboard and RIB diving with Ocean Addicts, www.oceanaddicts.ie. If diving individually use Admiralty Chart 1765, Old Head of Kinsale to Power Head. Cork diver Tony O’Mahony runs www.corkshipwrecks.net, with information on the Aud and many other wrecks.
Karl Spindler’s two books can be found secondhand and there are online transcripts and recent reprints. Other accounts can be found in The Sea and the Easter Rising by John de Courcy Ireland (ebook) and Courage Boys, We Are Winning by Michel Barry.

When I dived the Aud, it was pretty much levelled to the seabed. After a few days of south-easterly storms, I didn’t enjoy visibility or light anywhere near as good as that experienced by Diver?Chard.
My host, Graham Ferguson of Ocean Addicts, dropped the shot next to the boiler, the highest point on the wreck. Unusually, the boiler has been twisted to lie across the wreck. Everything else is pretty much in line with where it should be, as would be expected of a ship scuttled so cleanly.
Heading aft from the boiler, the engine crankshaft, thrust-bearing and propeller-shaft lead the way to the stern. The general direction of collapse is to starboard.
The cylinders of the triple-expansion engine (pictured) have fallen to starboard from the crank-shaft. Ammunition is easily found, rotting bullets piled almost everywhere in the areas of the holds.
Perversely, the stern has collapsed to port, so approaching along the starboard side of the wreckage the first indication of reaching the stern is the rudder, flat across the seabed.
Back past the boiler and forwards to the bow is more of the cargo of munitions piled towards the port side of the wreck, then the bow collapsed to starboard with the anchor-winch fallen to the seabed below.
The anchors were still in place at the bow, though I have since heard that they have been recovered and are now on display in Tralee and Cobh (formerly Queenstown).
It was only after I had swum the length of the wreck twice that outlines within a clump of debris in the forward hold finally clicked, and I recognised them as a mass of rifle stocks. Once my brain had switched on to the pattern, decayed remains of the Russian Mosin-Nagant rifles appeared everywhere.